My rifle doesnt like fast loads?

[Glennp]

My rifle really, really likes 41 grains 4895[IMR] under a 168gr AMAX (this is .308 BTW).
The rifle is my stock 700 with HS precision stock. Ive shoot under .5moa consitantly, with one instance shooting .18" CTC 5 round group. (100 yards)

I can pretty much seat the bullet anywhere, but shines at around .015-.02" off the lands.

It appears that this load according to hodgdon will be around 2447 FPS. Seems a bit slow to me. The rifle also likes 39.5 but thats way too slow for me...
Ive wandered up to 43.5gr without seeing any accuracy benifits. It just kinda gets worse, and levels out.

According to the hornady ballistic calculator, at 600 yards, this will have approx 1506 FPS behind it. Is that getting too slow to shoot well? Thats the max range I'll use this at.

 

[Victor N TN]

Re: My rifle doesnt like fast loads?

Try it and see if the bullet holes are keyholing. That is generally a good way to tell if they are still supersonic. What was the muzzle velocity?

Some rifles like a lighter load. The hottest is not ALWAYS the best.

 

[5R Milspec]

Re: My rifle doesnt like fast loads?

have you tried other powders?like varget,or 4064.these seem to work for me.even r15 works.in my 308 43-45g with the fist 2 powders works great for me.and Iam useing a 168 175g smk.could not get the 168g a-max to shot.but also give the other guys advice a try.if its not key holeing keep shooting it.
John

 

[Sig685]

Re: My rifle doesnt like fast loads?

Glennp, it really depends on what you are trying to do. Whether a load is too fast or fast enough or too slow, depends on your perspective. If your current load is extremely accurate and pleasant to shoot on top of that, it's hard to improve. If you are shooting at short range, say up to 300 yards, you should stay with this load and just enjoy the results.

Now you brought up the 600 yard range, is that something you are considering? If it is, then you need to get some more velocity, You should not be worried about keeping that round supersonic at 600, it is plenty supersonic, but to have it take less time to travel to 600 and be exposed to the elements, especially the wind.

A bullet has accuracy nodes and you seem to have found one at about 2450FPS. If you intend to shoot at 600 yards and beyond you may need to up the velocity to find the next accuracy node. When I was using the 168gr A-Max, I was loading the maximum charge of Varget, 46.0gr and in my 24 inch barrel, it was coming out at about 2720 FPS. The accuracy was decent, but that was more a function of the aging barrel. I have since switched barrel and alos moved on to a different bullet for 1000 yard competition.

The A-Max is a fine bullet, easy to load and get it to perform. You just need to decide what velocity you want and then find the accuracy node at or above that velocity.

 

[BLAWTON]

Re: My rifle doesnt like fast loads?

Has all your testing been at 100 yards?

 

[former naval person]

Re: My rifle doesnt like fast loads?

A lot also depends upon your cases and primers. My load of 40.3 gr of my older 4895 in Fed GMM cases, 210 primers, OAL 2.800, gives 2630 fps from my rifle with 168 Nosler J4's...loaded hotter I get shorter case life. Using Winchester cases I'd have to go up 1 to 2 grains to get the same velocity. I bet if you chrono the loads you'll get results that differ from Hodgdon's manual.